Moscow’s foreign minister, Sergey Lavrov, ruled out any dialogue with Ukraine’s new authorities, whom he dismissed as the puppets of extremists.

The Russians have denied their armed forces are active in Crimea, but an Associated Press reporter trailed one military convoy Saturday afternoon from 25 miles west of Feodosia to a military airfield at Gvardeiskoe north of Simferopol, over which a Russian flag flew.

Vladislav Seleznyov, a Crimean-based spokesman for the Ukrainian armed forces, said witnesses had reported seeing amphibious military ships unloading about 200 military vehicles in Crimea on Friday night after apparently having crossed the Straits of Kerch, which separates Crimea from Russian territory.

A small plane belonging to Ukrainian border guards was fired on by “extremists” as it flew near the administrative border of Crimea but took evasive maneuvers and escaped unscathed, the Interfax news agency reported, quoting Ukrainian officials.